Fax app needs assistance to fix fax distortion for iPhone

Apply only if you have experience & previously worked on Fax application. All other bids will be discarded. I am looking for someone to assist me with fax distortion problem I am facing. I am working on Fax application for a client and I am using Phaxio as a faxing services. When I am sending fax the output on the phaxio looks great but the output come through fax machine always distorts. I need someone to help me fix this problem. I have attached 1 image shows original image and distorted fax I am getting as an output. Please apply only if you have previous experience with phaxio and Fax application development.